There are test scores and there are test scores, so first I'd make sure that the expectations aren't too high based on a number that has questionable meaning. A 150 FSIQ on the SBV at 8 is a very different thing than one 150 score on the WPPSI at 3 or an IQ screening test which can be wildly inaccurate. Does she seem very advanced to you? Compared to other GT kids? Is there any subject area where she seems to struggle?
It surprises me that any kid with a post-preschool individual IQ test (SBV or WISCIV) of 150 full scale would struggle with any 4th grade curriculum. Even facing challenge for the first time, most 9 yo can adapt fairly well. It's not uncommon for a kid with similar scores to skip a grade or two or more and not even notice much. Having difficulty would make me worry about the accuracy of the score, the possibility of LD, or the emotional environment in the class. It seems there is a disconnect somewhere. She could be just adjusting to the work, but she might also be afraid of failure and dealing with perfectionism, showing her first signs of dyslexia or dysgraphia, or having a hard time with the other kids and/or teacher.
